boundary

[boun-duh-ree, -dree] / ˈbaʊn də ri, -dri /

NOUN

outer limit

Synonyms

STRONGEST

barrier border borderline bounds confines edge frontier horizon line perimeter

STRONG

ambit beginning borderland brink circumference circumscription compass end environs extent extremity frame fringe hem limits march margin mark mere mete outline outpost pale periphery precinct purlieus radius rim side skirt terminal termination terminus verge

WEAK

abuttals line of demarcation

Antonyms

STRONGEST

center inside interior middle

STRONG

opening start

WEAK

minimum

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

This remarkable effect occurs at a special condition known as the "Dirac point," where graphene sits at a boundary between being a metal and an insulator.

From Science Daily • Apr. 15, 2026

Maritime experts have said there is no legal argument for why Iran would be able to regulate commercial shipping on Oman’s side of the maritime boundary.

From The Wall Street Journal • Apr. 8, 2026

There was a crater, he said, on the nearside-farside boundary - a bright spot to the northwest of Glushko crater.

From BBC • Apr. 7, 2026

Drag was an important part of Ortiz’s approach to playing Jim Jimenez, the boundary breaking nonbinary pirate heartthrob on HBO’s cult show “Our Flag Means Death.”

From Los Angeles Times • Apr. 1, 2026

The river had curved around to the boundary of this neighborhood.

From "The Great Santini" by Pat Conroy

Vocabulary lists containing boundary

Human Geography - Middle School

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

Human Geography - High School

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

Political Geography - Middle School

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!